Atom 500 and NEO Low Values Cyclic and Collective

[norstaroption]

I just picked up a kit recently and getting very low values on both Cyclic throw and collective. Using Align DS515 servos with the stock compass servo horns. I have the ball link on the inner holes already.

Any suggestion?







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[Wargamer]

I went through the same thing a couple of months ago with my 5.5. The head geometry was never changed when they converted the Atom from FB to FBL, and this is normal. I'm using KST 589s with their horns; the distance is 15mm on my set-up and the geometry is definitely not 90 degrees. The numbers in the mini VBar are low and she still flies fine. (This is my first large heli so I really have nothing to compare it too other than the Oxy, but guys who know better and fly harder also have no issues...)

[stark]

I had to make a 3rd inner hole in the stock servo arms to make beastx happy at step J (blue light at 6 degrees). I then moved to vbar 5.x and had no issues with it there with the 3rd inner hole.

[Ah Clem]

Respectfull, this is not quite correct:

"I went through the same thing a couple of months ago with my 5.5. The head geometry was never changed when they converted the Atom from FB to FBL, and this is normal."

While the frame geometry was not corrected (resulting in the angle of the pushrods from the servo arms to the swashplate in the photograph), the head geometry was-the blade grip arms are different for the FBL version of the head.

The blade grip arms are larger, moving them further out from the spindle than the flybarred version of the head.

I have both heads (still have the flybarred head in storage somewhere).

The blade grip arms in the photograph do appear to be the correct ones for the FBL head.

The spacers between the balls on the upper deck of the swashplate were for the washout control for the flybarred version. These are not always used on the FBL version. This will affect the cyclic resolution (increasing the throw mechanically and making it more difficult to get the eight degrees for a V-Bar and the six degrees for the BeastX) and should not, necessarily, be present. They will work with FBL units that have different geometry requirements or are not as critical on cyclic throw (such as the old Robird) and reduce the tendency for the ball link to touch/rub the tapered part of the lower swashplate deck. They do not affect the collective throw.

I went out and got both my Robird equipped Atom and my V-Bar equipped one out. The one with the Robird has the spacers, the one with the V-Bar does not.

[Wargamer]

Originally Posted by Ah Clem

Respectfull, this is not quite correct:

Thanks for the expanded clarification!

[Ah Clem]

No problem, sir!

[lcc014]

Good to know that spacer is not needed in upper swashplate.

[Ah Clem]

If the ball links rub without the spacers, one or two thin washers under the ball will help.

[lcc014]

Thank you, Ah Chem.

I just wonder that we can still get a brand new Atom 500 today, like OP ? My is pre-owned....

[cyclo]

Originally Posted by Ah Clem

If the ball links rub without the spacers, one or two thin washers under the ball will help.

+1. This is what I did with my two Atoms... Two thin washers on the spline of the two servos in the front.

Originally Posted by lcc014

Thank you, Ah Chem.

I just wonder that we can still get a brand new Atom 500 today, like OP ? My is pre-owned....

The Atom kit has been discontinued for a while now. The Atom / stretched Atom is being replaced by the eXo.

[Ah Clem]

"The Atom kit has been discontinued for a while now. The Atom / stretched Atom is being replaced by the eXo."

Well stated, my friend!

As good as the Atom was/is, it is done.

It had a very, very long product life span (almost eight years since it was introduced in the Fall of 2008)-very unusual for any machine to last that long on the market-it was that good! It appeared towards the the end of the flybarred era and continued well through the flybarless revolution.

The eXo which will replace it (within the next few weeks now), is a radically new and extremely innovative design.

It will be a more than worthy successor.

[stark]

Originally Posted by cyclo

+1. This is what I did with my two Atoms... Two thin washers on the spline of the two servos in the front.

Cyclo, I think you are talking about something totally different than what Ah Chem is talking about. Adding washers in the servo spline is not going to affect cyclic resolution. Ah Chem was talking about reducing the washer thickness in the upper swash ball. However, this approach brings up another undesired problem. The grip links that go on the upper swash ball will come more closer to the swash ring and rub on it.

You can achieve a similar cyclic swash resolution increase by increasing washer thickness of the outer swash balls instead. However, you might need to use longer screws into the swash so that they don't come off in flight. I think this is when you will need to add washers on the front servo splines to get them in line with the swash balls.

[Wargamer]

Originally Posted by Ah Clem

If the ball links rub without the spacers, one or two thin washers under the ball will help.

I've been looking more closely at the swash after reading this thread a couple of times, and have noticed that the ball links on the drive tubes can rub the lower swash when cyclic and collective are both at extreme throws.

This doesn't worry me with the way I fly right now, but I'm curious if there is a specific shim or washer you would recommend in this application. It basically needs to be 2mm ID and no more than 3mm OD. Probably 0.5 to 0.7mm thickness I would guess.

EDIT: Answered my own question. Lynx actually makes a 2x3x0.5 brass washer and I happened to have a pair attached to a couple of broken DFC links from early in the summer. Good reason not to throw stuff out. Anyway, they seem to be just right as spacers for the drive tube balls.

[Ah Clem]

"I've been looking more closely at the swash after reading this thread a couple of times, and have noticed that the ball links on the drive tubes can rub the lower swash when cyclic and collective are both at extreme throws. This doesn't worry me with the way I fly right now, but I'm curious if there is a specific shim or washer you would recommend in this application. It basically needs to be 2mm ID and no more than 3mm OD. Probably 0.5 to 0.7mm thickness I would guess."

This is where I was suggesting to install the washers in post #8 above (as pointed out by Stark).

Cyclo's point about the washers being installed under the balls on the servo arms is correct-some servos need this due to variations in their deck height.

[lcc014]

Originally Posted by Wargamer

I've been looking more closely at the swash after reading this thread a couple of times, and have noticed that the ball links on the drive tubes can rub the lower swash when cyclic and collective are both at extreme throws.

This doesn't worry me with the way I fly right now, but I'm curious if there is a specific shim or washer you would recommend in this application. It basically needs to be 2mm ID and no more than 3mm OD. Probably 0.5 to 0.7mm thickness I would guess.

EDIT: Answered my own question. Lynx actually makes a 2x3x0.5 brass washer and I happened to have a pair attached to a couple of broken DFC links from early in the summer. Good reason not to throw stuff out. Anyway, they seem to be just right as spacers for the drive tube balls.

Where can we get this washer (2x3x0.5 mm) ? I tried Google and no can found....

[Wargamer]

In theory any Lynx dealer, but not easy to find. These guys have a good reputation:
https://tmkarc1hobby.com/sm20-35-05-...-5-10-pcs.html

[lcc014]

Originally Posted by Wargamer

In theory any Lynx dealer, but not easy to find. These guys have a good reputation:
https://tmkarc1hobby.com/sm20-35-05-...-5-10-pcs.html

Thank you for the link. The washer is not exactly as what you stated. It is 3.5mm outer diameter not 3mm. Would this rubs swashplate ?

[Wargamer]

Sorry - typo on my part. It is 3.5mm OD and it does fit without rubbing the swash.

[lcc014]

Thank you for the clarification.